Possible ampersand-state presenter

gistfile1.txt

var State = require('ampersand-state');
var _ = require('underscore');

function setupPresenterBindings (presenter) {
    Object.keys(presenter._deps).forEach(function (dep) {
        var parts = dep.split('.');

        if (parts.length !== 2) return;
        var presentee = parts[0];
        var property = parts[1];

        if (!presenter._definition[presentee] || presenter._definition[presentee].type !== 'object') return;

        presenter[presentee].on('change:' + property, function (model, value) {

            _.each(presenter._deps[dep], function (key) {
                var derived = presenter._derived[key];
                if (derived && derived.cache) {
                    var oldValue = presenter._cache[key];
                    var newValue = presenter._getDerivedProperty(key, true);
                    if (!_.isEqual(oldValue, newValue)) {
                        presenter._previousAttributes[key] = oldValue;
                        presenter.trigger('change:' + key, presenter, newValue);
                    }
                }
            });
        });
    });
}


function Presenter (attrs, options) {
    this.presents = attrs.presents;
    delete attrs.presents;
    State.call(this, attrs, options);
    setupPresenterBindings(this);
}

_.extend(Presenter.prototype, State.prototype);
Presenter.extend = State.extend;

module.exports = Presenter;